For some time, it has been a standard procedure in the motor vehicle manufacturing industry to integrate control devices for the engine or gearbox into the motor vehicle assembly to be controlled, i.e. the engine or gearbox. The gear control devices in particular form an extremely compact unit as an on-site control device. In comparison with the conventional use of external control devices, this arrangement has enormous advantages in terms of costs, weight, functionality and quality. In particular, this results in a significant reduction in plug-in connections and lines.
The integration of the control devices into the gearbox sets high demands on its thermal and mechanical resilience. The functionality must be guaranteed both within a broad temperature range (approx. −40° C. to 150° C.) and under strong mechanical vibrations (up to approx. 40 g). Since the control device is surrounded by gear oil, it must also be oil-tight.
A control device of this type is known from DE 199 07 949 A1. A housing lid and a base plate on which a two-dimensional, flexible foil conductor is applied, surround a hollow area. In this hollow area, an electronic circuit is arranged on the base plate in such a manner that it is surrounded on all sides by the flexible printed circuit board. Here, conductive paths on the flexible printed circuit board are connected via bond wires with corresponding contact pads on the interconnect device. The housing lid is mounted to the base plate in an oil-tight manner via a circular ring seal. The flexible printed circuit board is extended out of the hollow area of the control device housing between the ring seal and the base plate. The flexible printed circuit board creates the connection between the electronic circuit in the hollow area of the control device housing to the electrical components such as sensors or actuators outside the hollow area.
The flexible printed circuit board is a single piece. With complex arrangements of the control device and the surrounding components, this leads to a large amount of waste of printed circuit board material and is therefore not economical, even if one only calculates or considers the recess for the electronic circuit in the center of the flexible printed circuit board.
Furthermore, the position of the electrical components outside of the hollow area, for example, is determined by the form or shape of the flexible printed circuit board, and requires a change in the form of the entire flexible printed circuit board when the position of just one component is changed.